Nozzles are commonly used for the irrigation of landscape and vegetation. In a typical irrigation system, various types of nozzles are used to distribute water over a desired area, including rotating stream type and fixed spray pattern type nozzles. One type of irrigation nozzle is the rotating deflector or so-called micro-stream type having a rotatable vaned deflector for producing a plurality of relatively small water streams swept over a surrounding terrain area to irrigate adjacent vegetation.
Rotating stream nozzles of the type having a rotatable vaned deflector for producing a plurality of relatively small outwardly projected water streams are known in the art. In such nozzles, one or more jets of water are generally directed upwardly against a rotatable deflector having a vaned lower surface defining an array of relatively small flow channels extending upwardly and turning radially outwardly with a spiral component of direction. The water jet or jets impinge upon this underside surface of the deflector to fill these curved channels and to rotatably drive the deflector. At the same time, the water is guided by the curved channels for projection outwardly from the nozzle in the form of a plurality of relatively small water streams to irrigate a surrounding area. As the deflector is rotatably driven by the impinging water, the water streams are swept over the surrounding terrain area, with the range of throw depending on the radius reduction of water through the nozzle, among other things.
In rotating stream nozzles and in other nozzles, it is desirable to control the arcuate area through which the nozzle distributes water. In this regard, it is desirable to use a nozzle that distributes water through a variable pattern, such as a full circle, half-circle, or some other arc portion of a circle, at the discretion of the user. Traditional variable arc nozzles suffer from limitations with respect to setting the water distribution arc. Some have used interchangeable pattern inserts to select from a limited number of water distribution arcs, such as quarter-circle or half-circle. Others have used punch-outs to select a fixed water distribution arc, but once a distribution arc was set by removing some of the punch-outs, the arc could not later be reduced. Many conventional nozzles have a fixed, dedicated construction that permits only a discrete number of arc patterns and prevents them from being adjusted to any arc pattern desired by the user.
Other conventional nozzle types allow a variable arc of coverage but only for a very limited arcuate range. Because of the limited adjustability of the water distribution arc, use of such conventional nozzles may result in overwatering or underwatering of surrounding terrain. This is especially true where multiple nozzles are used in a predetermined pattern to provide irrigation coverage over extended terrain. In such instances, given the limited flexibility in the types of water distribution arcs available, the use of multiple conventional nozzles often results in an overlap in the water distribution arcs or in insufficient coverage. Thus, certain portions of the terrain are overwatered, while other portions are not watered at all. Accordingly, there is a need for a variable arc nozzle that allows a user to set the water distribution arc along a substantial continuum of arcuate coverage, rather than several models that provide a limited arcuate range of coverage.